1. Technical Field
The present invention relates to a fluid ejecting apparatus and a wiping method of the fluid ejecting apparatus.
2. Related Art
Heretofore, ink jet printers have been widely known as fluid ejecting apparatuses that eject fluid onto a medium. Such a printer is made so as to perform a printing process on paper (the medium) by ejecting ink (the fluid) from nozzles formed in a fluid ejecting head.
In such a printer, in order to stably eject ink droplets from the nozzles of the fluid ejecting head, the pressure in the fluid ejecting head, which is applied as a back pressure of a liquid in the nozzle, was normally set negative lower than the atmospheric pressure. In addition, such printers were sometimes provided with wipers for slidingly removing adherent materials (thickened ink, paper dust, and the like) formed on the nozzle formation face, on which the nozzle orifices are formed, of the fluid ejecting head (for example, JP-A-2001-063077 and JP-A-2008-221534).
In the printer disclosed in JP-A-2001-063077, a first surface of the wiper first comes into sliding contact with the nozzle formation face, thereby drawing out ink from inside the nozzle, and the adherent materials dissolved in the drawn-out ink are then scraped away by a second surface of the wiper that comes into sliding contact with the nozzle formation face after the first surface.
In the case of the printer disclosed in JP-A-2008-221534, by exuding ink in the nozzle to the nozzle formation face by pressurization and then by wiping, the adherent materials, which are dissolved in ink, are removed.
Incidentally, as with JP-A-2001-063077, when ink has been drawn out from inside the nozzle at the time of wiping, ink is supplied from the upstream side of the nozzle by capillary action. However, since the pressure at the back side of a liquid in the nozzle is normally set to be negative pressure, the ink is not sufficiently supplied to the nozzle when wiping is performed at high speed. As a result, air bubbles are mixed in the nozzle or the position of the liquid surface greatly retreats. This causes dot omission.
On the other hand, as with the printer disclosed in JP-A-2008-221534, if the back pressure of a liquid in the nozzle is set to be positive pressure, dot omission can be suppressed even when ink is drawn out from the inside of the nozzle as ink is supplied promptly. However, if the wiper comes into contact with the liquid surface exuded to the nozzle formation face, since the back pressure is positive pressure, there is a problem in which ink is wasted by continuously flowing out down the wiper.